Lighter having an improved piezoelectric ignition system

ABSTRACT

A gas lighter according to the invention has a weight slideable in a cavity within a housing of the lighter, the weight striking an abutment at the end of the cavity to stress a piezoelectric crystal and produce the ignition spark at the burner of the lighter. The weight is adapted to be moved to strike the abutment by gravity upon inverting the lighter, and or by giving the lighter a linear or centrifugal acceleration. The said weight may also serve to close and open a gas supply valve.

United States Patent Inventor Gabriel Riveron Le Vesinet, France Appl. No. 865,855 Filed Oct. 13, 1969 Patented Sept. 7, 197 l Assignee Soclete Flnminaire Marcel Quercla Paris, France Priority Oct. 16, 1968 France LIGHTER HAVING AN IMPROVED PIEZOELECTRIC IGNITION SYSTEM 2 Claims, 6 Drawing Figs.

[1.8. CI 431/255 Int. Cl F23g 2/28 Field of Search 431/255, 132

[56] References Cited UNITED STATES PATENTS 3,384,786 5/1968 Oyamda et al. 431/255 X 3,506,386 4/l970 Goto 431/255 3,521,987 7/1970 Goto 431/255 Primary Examiner-Edward J. Michael Attorney-Michael S. Striker ABSTRACT: A gas lighter according to the invention has a weight slideable in a cavity within a housing of the lighter, the weight striking an abutment at the end of the cavity to stress a piezoelectric crystal and produce the ignition spark at the burner of the lighter. The weight is adapted to be moved to strike the abutment by gravity upon inverting the lighter, and or by giving the lighter a linear or centrifugal acceleration.

The said weight may also serve to close and open a gas supply valve.

LIGHTER I'IAVING AN IMPROVED PIEZOELECTRIC IGNITION SYSTEM BACKGROUND OF INVENTION This invention relates to lighters of the type having a piezoelectric ignition system.

Lighters of this type are provided in a known manner with a housing, a burner supplied with fuel, an ignition system having at least one piezoelectric element electrically connected to a spark gap situated in the vicinity of this burner, and mechanical means for causing, when operated, mechanical stressing of the piezoelectric element to produce a spark in the spark gap.

The chief technical problem in the design of such devices has hitherto been the constitution and arrangement of the said mechanical means. If a piezoelectric element is to generate a voltage capable of producing a spark in a spark gap, it must be subjected to a considerable force which causes slight deformation of the piezoelectric element. It is difficult to generate such a force directly by hand. It has therefore been proposed that mechanical systems should be interposed between a control member operated by hand and the piezoelectric element, these mechanical systems converting the human force which acts on the control member and causes its displacement into a greater force which acts on the piezoelectric element and causes its deformation, which is smaller than the displacement of the control member.

Devices equipped with mechanical force-amplifying systems of this type, however, are bulky, heavy, complicated and unreliable in operation.

SUMMARY An object of the invention is to provide a lighter or the like whose mechanical means to stress the piezoelectric element are compact, light, simple, and very reliable in operation.

According to the present invention there is provided a lighter having an improved piezoelectric ignition system including a housing defining therewithin a cavity, a piezoelectric element, and a weight slideable in said cavity, said weight being capable of moving to produce the required strain in said piezoelectric element under the action of gravity and/or as a result of the lighter being accelerated.

The invention also relates to the method of igniting a lighter or the like comprising a piezoelectric ignition system, these devices being also of a manipulatable type, i.e. being adapted to be gripped and displaced manually.

According to the invention, the method of igniting a lighter or the like having a housing, a burner supplied with fuel and an ignition system with at least one piezoelectric element electrically connected to a spark gap situated in the vicinity of this burner, is characterized in that a weight, freely mounted in an elongated recess having an axis XX in the housing and adapted to move along the axis XX in the housing is subjected to acceleration directed along the axis XX and following a direction such that the weight is displaced and reaches an abutment situated at one of the two ends of the elongated recess, this abutment being adapted to transmit to the piezoelectric element the mechanical stressing to which it is subjected when struck by the weight.

DESCRIPTION OF DRAWINGS In order that the present invention will be more readily understood, several embodiments of a lighter according to the invention will now be described by way of example and with reference to the accompanying drawings in which:

FIG. I of the drawings illustrates, partly in elevation and partly in axial section, a gas lighter with a piezoelectric-igniting device according to the invention;

FIG. 2 and 3 illustrate, partly in elevation and partly in axial section, part of a lighter designed according to a variant, also according to the invention;

FIG. 4 and 5 show, in axial section in the rest and operative positions respectively, a gas lighter according to a different embodiment of the invention; and

FIG. 6 shows an axial section through a gas lighter according to a further embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a lighter having a housing 1, a burner 7 supplied with fuel from a liquefied-gas reservoir 13, and an ignition system having at least one piezoelectric element 2 electrically connected to a spark gap 9 in the vicinity of the burner 7.

Mechanical means are provided in order to generate, when operated, mechanical stresses on the piezoelectric element 2 so that a spark is produced in the spark gap 9.

These mechanical means include a weight 3 freely mounted in an elongate recess 4 having a longitudinal axis XX formed in the housing 1 of the lighter, this weight being movable along the axis XX within the recess solely as the result of the lighter being turned upside down or being given an acceleration having a component in the direction of the axis XX. An abutment 16 is situated at one of the two ends of the recess and is adapted to transmit to the piezoelectric element 2 the mechanical stressing to which it is subjected when struck by the weight 3.

As FIG. 1 illustrates, the piezoelectric element 2 is embraced by an electrically insulating sleeve 5. Advantageously, the element 2 is formed in two parts which face in opposite directions and grip one end of a conductor 6 whose other end leads to one of the electrodes of the spark gap 9, this electrode being constituted by the burner 7, formed by a metal tube which is electrically insulated from the other metal components of the lighter and through which the gas escapes.

The metal housing 1 is extended around the metal tube by a tubular portion 8 at the end of which the other electrode of the spark gap 9 is situated. This other electrode is directed towards the free end of the metal tube and is in electrical contact, by way of the lighter housing, with the opposite ends of the two portions of the piezoelectric element 2.

According to the embodiment illustrated in FIG. 1, the housing 1 is substantially in the form of a length of tubing equipped at one end with the assembly comprising the burner 7 and spark gap 9, and that portion of the housing 1 which is close to this assembly protects the piezoelectric element 2.

The remaining portion of the housing 1 forms the recess or cavity 4 in which the weight 3 can move.

The movement of the weight 3 which causes ignition is a movement towards the assembly comprising the burner 7 and spark gap 9.

As FIG. 1 shows, the end of the metal tube forming the burner 7 communicates by means of a duct 10 with a bell-type connection 11 of elastomeric material, mounted laterally on the outside of the tubular housing 1. A tubular reservoir 13, containing liquefied fuel gas under pressure, is pivoted at 12 on that end of the tubular housing 1 remote from the burner 7.

Near its free end, this reservoir has a gas discharge orifice around a pusher pin 14 facing the axis of the bell-type connecting 11. When this pin 14 is driven in, overcoming the action of a closing spring (not shown), the gas discharge orifice is opened.

A spring 15 mounted between the housing 1 and reservoir 13 tends to urge the pin 14 away from the bell-type connection 11.

In order to ignite the lighter shown in FIG. 1, it is merely necessary to place one hand round both the housing I and the reservoir 13, press them onto one another with the burner directed upwards and lower and invert them rapidly with a curved movement. During this movement, the weight 3 is displaced under the combined influence of centrifugal force and gravity, sliding in the recess 4 from the position shown in solid lines to the position shown by chain lines, in which the weight hits an abutment 16 covering the piezoelectric element 2. This piezoelectric element, compressed under the impact from the weight 3, generates a voltage which produces an electrical spark at the spark gap 9.

During this time, the reservoir 13 and housing 1, which have been pressed on to one another, have pivoted towards one another about the axis 12, enabling the annular lip on the belltype connection 11 to bear in a fluidtight manner on the wall of the reservoir 13 around the gas discharge orifice, and enabling the pusher pin to be driven right into the connection 1 1, opening the gas discharge orifice.

The gas stored under pressure in the reservoir 13 then escapes into the bell 11, from which the duct directs it to the outlet from the tube 7, where it is lit by the electrical spark produced at the spark gap 9.

The flame so ignited at the end of the tube 7 continues to burn as long as the reservoir 13 is being pressed onto the housing 1, overcoming the effect of the return spring 15.

The lighter according to the invention is therefore considerably simpler than known lighters, since it does not require any spring or loading and releasing means for a striker mechanism, or any lever to be operated at the same time as the gas discharge control means in order to subject the piezoelectric element to the mechanical stressing required for production of the ignition spark.

Also, since the housing enclosing the piezoelectric element and weight can be made completely fluidtight relative to the exterior, no foreign body can enter the recess. The lighter according to the invention is therefore particularly robust and reliable in operation. If the recess is fluidtight, sufficient clearance must be left between the weight and the recess to allow the air inside the recess to move freely.

It should also be noted that there is no control mechanism of the type provided in known lighters with piezoelectric ignition systems, to allow intervention from outside in order to subject the piezoelectric element directly or indirectly to the mechanical stress which makes it produce the high voltage required for ignition by means of an electrical spark.

Advantageously, the tubular portion 8 embracing the burner 7 contains a lateral air inlet [7 and bears a ring 18 by means of which this inlet 17 can be masked to a greater or lesser extent. As a result, the mixture of fuel and combustionsupporting agent to be ignited at the end of the burner 7 can be regulated.

The arrangement may be such that the ring 18 slides on the tubular portion 8 with an easy fit.

The ring 18 slides freely between two abutments on the tubular portion 8 under the influence of acceleration, so that, when the lighter is ignited, the ring can slide along the tubular portion 8 in the same direction as the weight 3 is sliding inside the recess 4, in order to reveal the air inlet 17, through which a certain quantity of combustion-supporting air passes to mix with the gas, promoting ignition.

The same ring 18 may mask the air inlet 17 by sliding in the opposite direction due to gravity when the lighter is righted. In this case, the flame which then comes vertically from the tube 7 is a soft, luminous flame.

Alternatively, of course, the ring 18 could play an opposite role, the abutments for the ring 18 on the tubular portion 8 being arranged differently so that, on ignition, the ring slides under the influence of acceleration to mask the air inlet 17, and when the lighter is righted, it slides in the opposite direction due to gravity and reveals the air inlet. In this case the flame which comes vertically out of the tube 7 is like a pointed blow-torch flame.

According to another arrangement, all the adjustments and automatic modifications of the type of flame desired between the moment of ignition and the moment of use may be obtained in a single lighter by using the design illustrated in FIGS. 2 and 3, in which like reference numerals, with the addition of a b index, designate the same elements as in FIG. 1. To this end, a socket 19, mounted with an easy fit on the tubular portion 817, contains two ports 20, 2], either of which, as desired, can be brought opposite the air inlet l7b or be offset to a greater or lesser extent relative to the air inlet by axial displacement and/or rotation on the tubular portion 8b. Abutments 22, 23 provided on the socket 19 on each side of the ports 20, 2i are adapted to limit axial sliding of a ring 18b on the socket 19. According to whether this ring is at one end of its stroke or the other, bearing on one of these abutments, it masks one and reveals the other of the two ports 20,21.

Assuming that by means of axial displacement, possibly combined with some rotation, the port 21 is brought more or less opposite the air inlet 17b (As shown in FIG. 2) and that the ring 181;, at the moment of ignition, is subjected to acceleration which displaces it from the position shown in solid lines to the position shown in chain lines, at the same time as it displaces the igniting weight inside the body of the lighter in order to make it strike the piezoelectric element, the air inlet 17b is revealed and the combustion-supporting air can mix with the fuel gas leaving the burner, at the instant at which the ignition spark is produced to ignite this mixture.

With the same lighter, the port 20 of the socket 19 can be brought opposite the air inlet 17b by displacing the socket 119 to the right on the tubular portion 8b (as shown in FIG. 3).

The lighter is then ignited in the same way, and the ring 18b, passing from the position indicated by solid lines to the position indicated by chain lines, instead of revealing the air inlet 17b, preventing combustion-supporting air from mixing with the fuel gas or (if there is another air inlet elsewhere) reducing the proportion of combustion-supporting air in the mixture at the moment of ignition.

The arrangement shown in FIGS. 2 and 3 therefore enables the mixture of fuel gas and combustion-supporting air to be modified as desired, according to the type of flame to be used on the burner, from the simple, luminous ignition flame to the bluish, pointed, blow-torch flame, and at the same time enables this mixture to be modified completely automatically at the moment of ignition to give it optimum proportions when ignited by the spark produced by the piezoelectric element.

As illustrated in FIG. 6, in which like reference numerals, but with the addition of the b index, designate the same elcments as in FIG. 1, the lighter according to the invention is in the form of a long, thin rod which, when held at one end, can be operated to produce and maintain a flame at its other end. With a lighter of this kind, in view of the length and thinness of the rod, a user can reach relatively inaccessible places, for example, burners for domestic or industrial ovens or radiators, and also remain some distance from the ignition site, protected from any flashback.

To this end, and as illustrated in FIG. 6, the housing 1b of the lighter has an elongated tubular form and comprises, one after the other, a gas reservoir in the form of an elongated cylinder 13b, a cylindrical cavity 4b for housing a weight 311, a piezoelectric element 2b and a burner 7b associated with an ignition spark gap 9b. The reservoir 13b is in the housing end portion, designed to be gripped manually, and the cavity 4b and the weight 31; which it contains are therefore remote from the grip joint, with the result that any angular movement of the grip subjects the weight 3b to a centrifugal force which urges it violently towards the piezoelectric element 2b.

It will be noted that, while the centrifugal acceleration is making the weight 3b slide along the recess 4b, which may be some tens of centimeters long, this acceleration must necessarily increase as the weight 3b moves away from the hand holding the lighter, and this increase tends to make the weight 3b strike the piezoelectric element 2b sharply, so producing a high voltage and ensuring ignition.

A pusher pin 14b projects from one end of the cylindrical reservoir 13b. When this pin is driven axially into the reservoir 13b, overcoming a return spring 29, the interior of the reservoir is connected to a gas discharge duct formed axially in the end of the pin 14b, so that the gas stored under pressure in the reservoir 13b can escape through the free end of the pin 1412 as long as the latter is still driven into the reservoir.

The pusher pin 14b and the gas discharge valve which it operates may be ofa conventional design, used for example by the designers of aerosol containers, and for this reason they will not be shown or described in more detail.

Advantageously, the reservoir 13b is a refill cartridge, easily replaceable in the cylindrical recess 26 provided for it in the lighter housing.

When the reservoir 13b is in its recess 26, its cylindrical pusher pin 14b is engaged in a connecting socket 27, passing through an annular packing 28 which provides a seal between the pusher pin and this socket. The socket 27 communicates with the burner 8b of the lighter by way of a duct 10b.

A compression spring 29, which bears on the end of the recess 26 (around the socket 27) and on the reservoir 13b (around the pusher pin 14b), holds the end of the pusher pin 14b off the end of the socket 27 by applying the end of the reservoir 13b onto a flat portion 30 of a sphere 31. On the opposite side of this sphere, a less-than-hemispherical portion of this sphere projects from the lighter housing through a circular port 32 in this housing, and carries a radial operating pin 33 centered on this portion.

Between the flat portion 30 of the sphere and the end of the reservoir 13b, a resilient spacer may be inserted, for example a resiliently compressible washer 34 clamped between two metal discs 35.

in order to supply gas from the reservoir 13b to the burner 7b, the pin 33 is pivoted out of alignment with the axis of the lighter housing (position shown in drawing) until its base abuts on the edge of the port 32, a position (not shown) which will be stable provided that the diameter of the port 32 is between those of the sphere 31 and of its flat portion 30.

During rotation of the sphere 31, in order to rise from the flat portion 30 onto the spherical portion of the sphere, the discs 35 moves to the left, pushing the reservoir 13b along the recess 26 in the same direction. The pusher pin 14b meanwhile penetrates further into the socket 27 and abuts on the end of the socket, whereupon it is pushed back towards the interior of the reservoir 13b, opening the gas escape valve for this reservoir. The gas leaves the pusher pin 14b axially, enters the socket 28 and flows along the duct 8b, which takes it to the burner 7b.

The user, who is holding the lighter by the end containing the reservoir 13b, the burner 7 b facing upwards, then simply sweeps the lighter through the air causing the housing lremote from the hand to rotate about the hosing end gripped in the hand.

Alternatively, the user could direct the burner 7b towards the ground, but in any event the weight 3b, leaves the position shown in the drawing and strikes the piezoelectric element 2b, which produces the ignition spark in the spark gap 9b provided in the burner 712.

To stop the supply of gas to the burner 7b, the pin 33 is brought into alignment with the lighter axis, so that the reservoir 13b, under pressure from the spring 29, can retreat along the recess 26 towards the flat portion 30 of the sphere 31, and the pusher pin 14b can reemerge from the reservoir and close the gas discharge valve.

In the embodiment illustrated in FIGS. 4 and 5, in which like reference numerals with the addition of an index a designate the same elements as in FIG. 1, that end of the recess remote from the piezoelectric element 2a has a pusher pin 25, introduction of which causes closure of a discharge valve supplying gas to the burner 7a connected to the reservoir 13a.

FIG. 4 shows the rest position of the lighter, in which the weight 3a ensures that the pusher pin 25 is in and the discharge valve closed.

Any movement of the weight 3a towards the piezoelectric element 2a due to acceleration, more particularly acceleration due to gravity, leads first to opening of the discharge valve, and then to the abutment 16a being struck so that a spark is produced in the spark gap 9a.

FIG. 5 shows the operating position of the lighter. When the lighter assembly is turned over, to bring it from the rest position shown in fig. 4 into the operating position shown in FIG. 5, the weight 3a fails a distance it, moving away from the pusher pin 25 which, being released, allows the gas contained in the reservoir 13a to escape through the burner 7a and, striking the piezoelectric element 2a (which is electrically connected to the spark gap 9a in a fashion similar to that shown in more detail in the lighter shown in FIG. l), ignites the gas coming from the burner 70 with an electrical spark.

As long as the lighter is left in a vertical position, either resting on a table 24 or held in the hand, the flame on the burner continues to burn.

To extinguish this flame the lighter assembly is simply turned over. The weight 3a falls back across the recess 4a by the distance it, moving away from the piezoelectric element 2a and pushing the pin 25 back in so that the connection between the pressure gas reservoir 13a and the burner 7a is broken. In this position, also, the weight 3a resting on the end of the recess 40 in which the pusher pin 2 projects, is ready for the next ignition operation, since it is off the piezoelectric element 20 which is mounted at the opposite end of the recess 4a.

Obviously, if the impact of the weight 30 on the piezoelectric element 2a, after a free fall by a distance it, is insufficient, the lighter may be ignited by jerking it vertically to increase the acceleration of the weight 3a or, if the lighter is to be put on a table, by hitting the surface of this table with the lighter assembly.

It will be appreciated that in the case of each of the lighters described above, the weight may be moved under gravity and/or as a result of the lighter being accelerated, either linearly or centrifugally.

I claim:

1. A lighter having a burner embraced by a tube, and an improved piezoelectric ignition system, said system including a housing defining therewithin an elongate cavity, a piezoelectric element, and a weight slideable in said cavity, said weight being capable of moving to produce the required strain in said piezoelectric element under the action of gravity and/or as a result of the lighter being accelerated, said tube having a longitudinal axis aligned with the longitudinal axis of said elongate cavity, a ring embracing said tube and a lateral air inlet in said tube, said ring being slideable on said tube between a first terminal position in which said ring masks said lateral air inlet and a second terminal position in which said ring exposes said lateral air inlet, said ring being slideable between said first and said second terminal positions under the influence of whatever forces serve to cause movement of said weight.

2. A lighter having a burner embraced by a tube and an improved piezoelectric ignition system, said system including a housing defining therewithin an elongate cavity, a piezoelectric element, and a weight slideable in said cavity, said weight being capable of producing the required strain in said piezoelectric element under the action of gravity and/or as a result of the lighter being accelerated, said tube having a longitudinal axis aligned with the longitudinal axis of said elongate cavity, a sleeve having a pair of axially spaced air entry apertures pivotally embracing said tube and a lateral air inlet in said tube, said sleeve being adjustable on said tube whereby one or other of the air entry apertures may be set to overlap with said lateral air inlet to the desired extent, a ring embracing said sleeve, said ring being slideable on said tube between a first terminal position in which said ring masks one said air entry aperture and a second terminal position in which said ring masks the other said air entry aperture, said ring being slideable between said first and said second terminal positions under the influence of whatever forces serve to cause movement of said weight. 

1. A lighter having a burner embraced by a tube, and an improved piezoelectric ignition system, said system including a housing defining therewithin an elongate cavity, a piezoelectric element, and a weight slideable in said cavity, said weight being capable of moving to produce the required strain in said piezoelectric element under the action of gravity and/or as a result of the lighter being accelerated, said tube having a longitudinal axis aligned with the longitudinaL axis of said elongate cavity, a ring embracing said tube and a lateral air inlet in said tube, said ring being slideable on said tube between a first terminal position in which said ring masks said lateral air inlet and a second terminal position in which said ring exposes said lateral air inlet, said ring being slideable between said first and said second terminal positions under the influence of whatever forces serve to cause movement of said weight.
 2. A lighter having a burner embraced by a tube and an improved piezoelectric ignition system, said system including a housing defining therewithin an elongate cavity, a piezoelectric element, and a weight slideable in said cavity, said weight being capable of producing the required strain in said piezoelectric element under the action of gravity and/or as a result of the lighter being accelerated, said tube having a longitudinal axis aligned with the longitudinal axis of said elongate cavity, a sleeve having a pair of axially spaced air entry apertures pivotally embracing said tube and a lateral air inlet in said tube, said sleeve being adjustable on said tube whereby one or other of the air entry apertures may be set to overlap with said lateral air inlet to the desired extent, a ring embracing said sleeve, said ring being slideable on said tube between a first terminal position in which said ring masks one said air entry aperture and a second terminal position in which said ring masks the other said air entry aperture, said ring being slideable between said first and said second terminal positions under the influence of whatever forces serve to cause movement of said weight. 